This invention relates to a power supply arrangement for providing auxiliary power to the electrical system of a building, such as from a standby generator or the like.
Portable generators are used in certain situations to supply electrical power to residential and commercial load circuits during a utility power outage. A system for interconnecting the generator with the load center of a building typically includes a power inlet box having a receptacle for receiving a plug extending from the generator.
The power inlet box is typically mounted to the exterior of a building, and is adapted for connection to a transfer switching mechanism which establishes an electrical path between the generator and the load center. The transfer switching mechanism typically includes a series of switches and circuit breakers, which are operable to supply power to certain selected circuits of the load center. The circuits of the transfer switching mechanism are wired to selected circuits of the load center, through wiring housed within a conduit extending between the transfer switching mechanism and the load center.
A typical transfer switching mechanism includes a housing provided with a power input receptacle. The remote power inlet box may be wired to a power cord connected to a junction box, and the power cord is engageable with the power input receptacle of the transfer switching mechanism so as to provide power to the transfer switching mechanism from the generator. An alternative arrangement is illustrated in Flegel U.S. Pat. No. 5,895,981 issued Apr. 20, 1999, the entire disclosure of which is hereby incorporated by reference. In the '981 patent, the transfer switching mechanism includes a terminal compartment within which a set of terminals is located. The terminals are wired to the switches of the transfer switching mechanism. A set of power input wires extends from the power inlet box, and into the terminal compartment of the transfer switching mechanism. The ends of the power input wires are connected to the terminals, to establish a direct, non-plug type connection between the power inlet box and the transfer switching mechanism.
U.S. Pat. No. 6,414,240 issued to Flegel on Jul. 2, 2002, the entire disclosure of which is hereby incorporated by reference, describes a power transfer switching mechanism that includes a cabinet defining an internal cavity within which a series of switches are mounted. One or more lead wires are connected to the switches, and define ends which extend into a compartment. The compartment is accessible through an opening associated with the cabinet, and a cover is selectively positionable over the opening to provide or prevent access to the compartment. With the cover removed, the lead wires can be connected to power input wires in a conventional manner, e.g., using wire-to-wire connectors, and the wires and the connectors may then be placed within the compartment and concealed by attaching the cover to the cabinet.
Commonly owned U.S. patent application Ser. No. 12/897,354, now issued as U.S. Pat. No. 8,310,818, titled “Transfer Switch Housing Having a Removable Wall For Segmenting the Housing Into A Pair of Compartments,” the entire disclosure of which is incorporated herein, provides a power transfer switching mechanism that improves upon the advancements to the art provided by the '240 patent to Flegel. More particularly, the power transfer switching mechanism disclosed in the '354 Application includes a housing having a base that defines an internal cavity that is segmented into first and second compartments, which may be in the form of upper and lower compartments, by an intermediate and removable wall member. The base is generally defined by a back wall and a pair of sidewalls extending outwardly from the back wall, and which may be integrally formed with the back wall. A mating engagement arrangement is interposed between the base and the intermediate wall member. The mating engagement arrangement may be in the form of a channel formed along the inner surface of the back wall and along facing inner surfaces of the sidewalls, and functions to partition the base into first and second sections, which may be an upper section and a lower section. The intermediate wall member has an opening that defines a passageway between the first and second sections for passing wires between the first and second sections.
The housing includes an enclosure arrangement that is engaged with the base and the intermediate wall member and which is configured to enclose the interior of the housing. In one embodiment, the enclosure arrangement includes a first (or upper) panel that engages portions of the sidewalls and the intermediate wall member, and that is configured to fit over the first section to define the first or upper compartment. In a similar fashion, the enclosure arrangement includes a second (or lower) panel that engages portions of the sidewalls and the intermediate wall member, and that is configured to fit over the second or lower section to define the second or lower compartment. The panels may have end wall portions that, in one embodiment, define a top and bottom of the housing when engaged with the base. The plurality of switches associated with communicating power through the transfer switch housing are supported or otherwise positionally secured to a front face that removably cooperates with the intermediate wall member such that removal of the front face exposes those portions of the various switches and/or breakers that are generally behind the front face and such that all the switches associated with the enclosure arrangement translate relative to the base during movement of the intermediate wall.
The present invention provides a further improvement of a transfer switch assembly wherein various switches or breakers are supported and electrically connected by a bus bar associated with the rear wall of the enclosure space such that a movable cover and a front face member or panel can be removed from the transfer switch assembly without effecting the position and orientation of the various electrical switches and/or power indicators relative to the base of the transfer switch assembly, thereby allowing manipulation or service of discrete breaker elements relative to the transfer switch assembly without exposing the electrical connections associated with a service panel. Representatively, the transfer switch assembly is configured to receive and operate with one or more 1-inch interchangeable breakers. The transfer switch assembly may be configured for operation with one or more, 1-inch circuit interrupters, 1-inch ground fault circuit interrupters (GFCI), 1-inch arc fault circuit interrupters (AFCI), and/or combinations thereof. Such a configuration provides a transfer switch assembly having a switch and breaker assembly that is more readily serviceable and provides improved arc and ground fault circuit protect.
In one aspect, the present invention contemplates a power transfer device adapted for interconnection with the electrical system of a building. The power transfer device includes a cabinet, a set of switches mounted to the cabinet, and wires adapted to connect the switches to an electrical distribution panel associated with a building electrical system. The power transfer device includes a first compartment and a second compartment partitioned from one another by a removable intermediate wall that may slidably engages a base that defines a back wall of the cabinet. The set of switches removably cooperate with a bus bar secured to the back wall of the base of the cabinet. A first panel closes the first compartment and cooperates with the set of switches such that the switches are operable through the first panel and discrete switches can be removed from the cabinet when the first panel is the removed from cabinet without interfering with an orientation of other switches relative to the cabinet.
Another aspect of the invention that includes one or more features combinable with the above aspects contemplates a power transfer arrangement having a base member that includes a back wall that defines first and second ends of the base. An intermediate wall is engaged with the base member at a location between the first and second ends of the back wall. An enclosure arrangement is engaged with the base member and with the intermediate wall. The enclosure arrangement cooperates with the base member to define an interior of the power transfer arrangement, and the intermediate wall is configured to separate the interior of the power transfer arrangement into a first interior section and a second interior section. Power transfer switching components are disposed in the first interior section and carried by the base. The power transfer switching components are accessible through the enclosure arrangement when the enclosure arrangement is engaged with the base.
Another aspect of the invention combinable with one or more of the above aspects contemplates a transfer switch arrangement that includes a base having a first section and a second section. An intermediate wall removably engages the base and defines an end of the first section and an end of the second section. An enclosure arrangement cooperates with the first section of the base and the intermediate wall to define a first compartment, and also cooperates with the second section of the back wall and the intermediate wall to define a second compartment. One or more power transfer switching components, which have switch bodies disposed between the enclosure arrangement and the base, removably cooperate with a bus bar that is secured to a rear wall of the base in the first compartment.
Various other features, aspects, and advantages of the invention will be made apparent from the following description taken together with the drawings.